The present invention is directed to an ink-jet applicator using UV curable ink, coating or adhesive and particularly to an ink-jet applicator having means for curing the UV curable ink, coating or adhesive just after it has been deposited onto a work surface.
There are several types of print heads which are capable of producing a finely directed stream or droplet flow of ink to a surface which is moving relative to the print head. By applying digitized signals, which has been resolved and rasterized from an image, to the print head, a digital print is produced. Typically, in large-format digital printing, the print head is moving in one direction while the work surface or sheet is moved in a perpendicular direction. These two motions, in combination with an ink color and impulse signal sent to the print head, produce an image which builds, line-by-line, on the work surface. This method of plotting is well-established and commonly used.
UV curing of the ink is most effective when applied immediately or as soon as practical after the deposition of the ink. The UV radiance required to cure opaque inks is in the range of 1-20 watts/cm2, and may be anywhere in the range of 200 nm through visible light wavelengths. This suggests mounting the exposure lamp on the print head mechanism, in order to follow the print closely. However, higher speed printing requires the total mass of the print head be as low as possible.
It is an object of the present invention to provide an ink-jet applicator using UV curable ink, coating or adhesive that provides curing of the liquid immediately after deposition on the work surface.
It is another object of the present invention to provide an ink-jet applicator for UV curable ink, coating or adhesive with the capability of the curing the liquid immediately after deposition while keeping the total mass of the print head relatively low.
In summary, the present invention provides an ink-jet applicator comprising a print head including a housing; a guide operably secured to the housing to guide the housing across a medium being imprinted; a UV light source disposed at one end of the guide to generate a beam of radiation; and a mirror carried by the housing adapted to reflect the beam onto the UV curable coating deposited by the print head onto the work surface.
The present invention also provides a method for curing UV curable coating applied with an ink-jet applicator, comprising providing a print head movable along a guide across a work surface to be imprinted; providing a UV light source at one end of said guide to generate a beam of radiation; and reflecting the beam onto the coating just deposited by the print head onto the work surface.
These and other objects of the present invention will become apparent from the following detailed description.